Muffler with diagonal tube ends



prll 29, 1969 F. R. HUBBELL nl MUFFLER WITH DIAGONAL TUBE ENDS FiledJuly 18, 1966 INVENTOR.

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(c (IIIIIIIIIOC/k United States Patent O 3,441,105 MUFFLER WITH DIAGONALTUBE ENDS Franklin R. Hubbell III, Brooklyn, Mich., assignor to WalkerManufacturing Company, Racine, Wis., a corporation of Delaware FiledJuly 18, 1966, Ser. No. 565,829 Int. Cl. F01h 7/08 U.S. Cl. 181-61 2Claims ABSTRACT OF THE DISCLOSURE A component tube for a mufller isformed with the ends parallel to each other and slanted to the tube axisso that when mounted in supporting flanges the tube contains materialthat overlaps substantially less than all of the flange therebyeffecting a substantial saving in the amount of metal used in the tube.

My invention relates to mufllers and in particular to mufllersmanufactured in huge quantities such as automobile exhaust mulllers.

It is an object of my invention to reduce the cost of mufllers withoutin any way interfering with their quality and performance.

The invention accomplishes the foregoing by shaping the ends of thetubular parts used in mufllers so that they lie in a plane which isdiagonal instead of normal to the axis of the tube. In this way a smallsaving in material is made for each tube which, when totaled up -for theseveral tubes in a mutller and for the millions of mufllersmanufactured, amounts to a very substantial saving in cost of metal usedto fabricate the mufllers.

The invention is illustrated in the accompanying drawings, in which:

FIGURE 1 is a longitudinal cross section for a typical exhaust muffler;

FIGURE 2 is an enlarged cross section along the line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged view of the structure within the circle 3 ofFIGURE l; and

FIGURE 4 is a reduced view showing the blank that may be used to formthe tubes used in the mufller.

The mufller 1 has an outer shell 3 which may be surrounded by a layer ofasbestos and metal to provide insulation 5. The inlet end of the housing3 is closed by the header 7 and the outlet end by the header 9. Spotwelded in position inside of the shell 3 are flanged partitions 11, 13and 15 which define longitudinally separated chambers 17, 19, 21, and 23within the mufller shell 3. Extending through the inlet header 7 andsupported in a flange 25 formed therein is an inlet bushing 27. Theinner end of the bushing 27 extends through and is spot Welded to aflange 29 in the partition 11. Supported in the inner end of the bushing27 is the inlet end of a gas flow tube 31 and this extends through anecked opening 33 in partition 13 and is supported in a flanged neck 35in the partition 15. The partitions 13 and 15 also have a pair offlanged necks 37 and 39 which support the opposite ends of a return flowtube 41. The partitions 13 and also have flanged necks 43 and 45 whichsupport an outlet tube 47 which also extends into an outlet bush ing 49that is formed in the header 9.

The portions of tubes 31, 41 and 47 within the chamber 21 are louveredas indicated in the drawings, and the "ice louvers in tube 31 aresurrounded by a double pancake construction 51 which provides a pair ofsmall volume spit chambers 53 for silencing relatively high frequenciesand roughness in the gas. The chamber 17 is connected through a. tuningtube 55 to the chamber 19 and therefore acts as `a Helmholtz resonatorthat may be tuned to silence a. selected relatively low frequency in thegas passing through the mufller.

Exhaust gas enters the inlet bushing 27 and passes along the pipe 31into chamber 23 where it reverses direction to flow forwardly throughthe return flow tube 41. In chamber 19 it reverses flow again and passesout of the muffler through the tube 47. While the gas is in the varioustubes within the chamber 21, the connection with the volume of thechamber through louvers in the tubes or with t'he spit chamber 51,enables high and medium frequencies to be attenuated. As alreadyindicated relatively low frequency is attenuated by -means of theHelmholtz resonator comprising chamber 17 and tuning tube 55.

In accordance with the invention and as visible in the drawings certainof the tubes, namely, 31, 41, 47, and 55 have the opposite ends formedon a bias or taper, the opposite ends being parallel to each other. Theangle of the end faces with respect to the axis of the tube is smallenough so that tubes can still be adequately supported in the variouspartition flanges and welded to them where desired.

Assuming that the various tubes are formed by rolling up originally flatsheet metal as indicated by the tube interlock joints in FIGURE 2, itwill be seen from FIG- URE 4 that the effective length 57 of the tubeand blank is somewhat greater than the actual blank lengths 59 becauseof the slanted ends 61 and 63. Accordingly, there is a saving inmaterial which -when multiplied by millions of units amounts tosomething which is quite substantial. The same saving can be effected intubing that is of the seamless type by cutting off the individual piecesof tubing along Ithe parallel diagonals as indicated.

It will now be realized that the invention provides an effectiveexpedient for substantially reducing the total material cost of mufllerswhen manufactured in high production and that this is done withoutinterfering with the performance or quality of the mufller.

Variations in the specific structure illustrated may be made withoutdeparting from the spirit and scope of the invention.

I claim:

1. A muffler for silencing gases comprising a housing having an inletand an outlet, means inside said housing for conveying gases from theinlet to the outlet and silencing gases within the housing, said meansincluding a tube having opposite ends, said tube having an axis, saidopposite ends being parallel to each other and making an angle with saidaxis which is different than tube support means in said housing for eachend of said tube and each tube support means having an opening and anannular flange around said opening, said annular flanges being coaxialwith said tube and the planes of each opening being perpendicular to theaxis of the tube, the ends of said tube being mounted in said annularflanges, the length of said flanges and the angle of the ends of thetube being such that the axial length of said tube ends are includedbetween the opposite ends of said flanges.

2. A mulller for silencing gases comprising a housing having an inletand an outlet, means inside said housing for conveying gases from theinlet to the outlet and silencing gases within the housing, said meansincluding a straight tube having opposite end edges that lie in flatplanes that are parallel to each other, a tube support member in saidhousing having an opening in a face thereof to receive an end of saidtube and lhaving an annular tube support surface adjacent to saidopening so that one end of said annular surface defines said opening,said tube having an end extending into said opening and supported onsaid annular surface, said opening dening a at plane that isnon-parallel to the plane defined by the end of the tube extendingthrough it so that the length of tube that is supported on said annularsurface varies as measured along lines on the support' surface which areperpendicular to the plane of the opening.

4 References Cited UNITED STATES PATENTS 2,205,024 6/ 1940 Zinsitz.2,824,619 2/1958 Bremer et al 181-72 XR 3,043,393 7/1962 Hopkins 181-49XR 3,243,012 3/1966 Powers 181-54 XR FOREIGN PATENTS 221,877 6/ 1962Austria. 455,590 4/ 1949 Canada. 1,351,921 12/1963 France.

ROBERT S. WARD, JR., Primary Examiner.

U.S. Cl. X.R. 181-54, 72

